Table of ContentsView AllTable of ContentsAge EffectsMeasuringSleep StagesWhy You Need Deep SleepHow to Get More Deep Sleep

Table of ContentsView All

View All

Table of Contents

Age Effects

Measuring

Sleep Stages

Why You Need Deep Sleep

How to Get More Deep Sleep

Deep sleep, like all sleep stages, helps you feel refreshed when you wake up. The proportion of time you need to spend in each sleep stage varies with age. Adults need around 20% to 25% of total sleep time in deep sleep, which comes out to a total of one to two hours of deep sleep per night.People who do not sleep soundly can usestrategies to help get more deep sleep.How Age Affects Your Need for Deep SleepThe total number of hours you need to sleep changes with age. According to the Centers for Disease Control and Prevention (CDC), children and adolescents need more sleep than adults.Sleep needs per age:Up to age 1: 12 to 17 hoursAge 2 to 5: 11 to 14 hoursSchool age: Nine to 12 hoursTeenagers: Eight to 10 hoursAdults: Seven to nine hoursSometimes, people think they may need less sleep during older adulthood, but this is not true. Older adults need seven to nine hours of sleep, but sometimes medical problems, likesleep apnea(pauses in breathing during sleep), may interfere with sleep, especially during older age.How to Know How Much You Are GettingYou can learn how much sleep you are getting in several ways. You can gauge how you’re feeling the next day or use a device to get an approximate measure of your time spent in eachsleep stage.The simplest and most common way to know if you’ve had enough sleep and enough deep sleep is based on how you feel in the morning. Long before electronic devices emerged for measuring sleep, people could often sense whether they got enough rest.Signs that you’ve had enough deep sleep include:You don’t feel like you are still in a dream state.You are ready to open your eyes wide.You are ready to get out of bed.You can feel comfortable in a well-lit room.You are able to move your body around and start your morning routine.Some signs that you might not have had enough sleep include waking up with a headache, feeling like a bright light is bothering your eyes, wanting to crawl back into bed, or feeling a little bit unsure if you are still dreaming.What Is Sleep Inertia?Sleep inertiais that feeling you get when you first wake up and you still feel groggy or even a little confused. Waking up during deep sleep, especially if you haven’t had enough deep sleep, often causes sleep inertia.Diagnostic tests and tests of at-home devices can also detect if you have had enough sleep.A comprehensivepolysomnogramis a diagnostic sleep study usually done in a sleep laboratory. This test measures your brain’s electrical activity, body temperature, heart rate, eye movements, and physical movements. Using these parameters, a sleep study can estimate your time in each sleep state.At-home sleep devices include watches or rings that detect changes in your body temperature, physical movements, and heart rate that correlate with sleep stages. These devices provide a range of accuracy regarding your sleep stages.I’m a Light Sleeper: Tips to Get Better SleepSleep Stages and Deep SleepDuring a full night of sleep (or even during a nap), you experience several changes in your brain activity that are detected as brain waves. Additionally, your body goes through measurable physical changes. The brain wave changes correlate with changes in heart rate, body temperature, and physical movements.Sleep stages are:Stage 1: In the earliest stage of sleep, you begin to lose awareness of what is going on around you, and you start to get some rest. If there are noises or other disruptions in the environment, you might wake up easily during this stage.Stage 2: During this stage, you often toss and turn during sleep, and you may wake up if someone gently tries to get your attention while you’re sleeping. The brain waves slow down a bit at this stage.Stage 3: This sleep stage is often described as a slow wave sleep because of the characteristic polysomnogram pattern that is detected during this stage. Usually, people toss and turn and do not easily wake up in response to disruption in the environment during stage 3 sleep.Stage 4: Many descriptions of sleep stages do not include stage 4—and instead blend this into stage 3. Sometimes, the description of sleep stages includes stage 4 sleep, which is similar to stage 3, but involves deeper sleep, and slower waves on EEG.Rapid eye movement (REM) sleep: During this stage of sleep, you have dreams, even if you don’t remember them. Some key physical changes during REM sleep are that your eyes move under your closed eyelids and you do not toss and turn or move around. While REM sleep isn’t usually classified as a deep sleep stage, most people don’t wake up easily during the dreaming sleep stage.During a typical seven- to nine-hour night of sleep, most adults cycle through four to six cycles of non-REM (NREM) and REM sleep stages.Is REM or Deep Sleep Better?There’s really no way to designate any sleep stage as being better than the others. All sleep stages are important for your memory and for your emotional and physical well-being.Why You Need Deep SleepDuring deep sleep, your body makes hormones (chemical messengers) and proteins that promote cell growth and renewal, for replenishing and healing your body’s tissues.Processes during deep sleep include:Increased blood flow to your musclesCell and protein regenerationHealing and repair of your tissuesGlucose (sugar) regulationEnergy productionHormone releaseGrowth, especially during childhoodThese different tasks can help your body maintain optimal function, producing new cells and tissue to replace those that need to be replaced. Additionally, repairing any injuries or damage to your body’s tissues helps prevent long-term disease.Children experience a lot of growth during deep sleep. In addition to the growth of physical tissue, such as muscles, bones, and skin, deep sleep also helps with memory consolidation (new memories are turned into long-term memories) and improving daytime learning ability.I’m a Light Sleeper: Tips to Get Better SleepWhat Happens If You Don’t Get Enough Deep Sleep?If you don’t get enough deep sleep, you will likely feel tired the next day. Being tired can feel different for different people, and your own self-awareness of feeling tired can differ, depending on your age, goals, and overall personality. You might feel sluggish, grumpy, agitated, or have trouble concentrating.A chronic lack of deep sleep over a long period of time can gradually affect your physical and mental health. If you frequently feel irritable, unmotivated, or tired, this can interfere with your relationships with others, and you can also make you unproductive and depressed.The physical effects of not getting enough deep sleep can lead to premature aging and may also impair your body’s ability to heal from injuries and illness.Eventually, this could lead to serious medical conditions, such as heart disease and cancer.Sleep LatencySleep latencyis the amount of time it takes you to fall asleep. For typical healthy adults, it is between 10 and 20 minutes. If you are lacking a specific stage of sleep—especially deep sleep,you might fall into a deep sleep state immediately when you go to bed, rather than cycling through the earlier stages of sleep.So, a lack of deep sleep can cause you to miss out on other sleep stages, too.How to Get More Deep SleepIf you’re not getting enough deep sleep, you can consider strategies to increase your total and deep sleep time. Some daytime actions can impact your nighttime sleep, and you can change your sleep environment to help yourself get enough deep sleep.Alcoholand caffeine are two common substances that interfere with deep sleep. Avoiding alcohol and caffeine in the evenings, or even throughout the day—at any time of the day or night—can help you get a natural sequence of sleep stages.Other things you can do to help yourself get enough deep sleep include:Make sure the temperature of your bedroom is comfortable. An ideal temperature to increase deep sleep is 60 to 68 degrees F, but it varies per person.Use blankets that are comfortable for you and that promote rest.Have a relaxing and consistent bedtime routine.Avoid eating a heavy meal for three hours before bed.Consider doing light stretches or other relaxing exercises a few hours before bed.If you have a medical issue that’s preventing you from getting enough deep sleep—like sleep apnea or chronic pain—follow through with the recommended treatment.Try to clear your mind of anxiety before you go to bed. Since life almost always includes some difficulties, consider putting challenging or stressful tasks in a time slot for the next day to avoid anxiety while you’re trying to sleep.Many people feel that heavy orweighted blanketsprovide a sense of relaxation, which can help you fall asleep. If you feel that the weight of heavy blankets helps you feel comfortable but makes you feel too hot, you could consider adjusting the room temperature so you can improve your overall sleep experience.SummaryDeep sleep is important for your health, and even for your survival. Most adults spend about 20% to 25% of total sleep time in deep sleep stages, which include several blocks throughout a typical night of sleep. If you don’t get enough deep sleep, you could have an increased risk of health problems and may have a hard time recovering from illness or injury.Strategies to get enough deep sleep include making sure your sleeping environment is comfortable, avoiding caffeine and alcohol before bed, and maintaining a relaxing routine before bedtime.What Is Sleep Deprivation?

Deep sleep, like all sleep stages, helps you feel refreshed when you wake up. The proportion of time you need to spend in each sleep stage varies with age. Adults need around 20% to 25% of total sleep time in deep sleep, which comes out to a total of one to two hours of deep sleep per night.People who do not sleep soundly can usestrategies to help get more deep sleep.

How Age Affects Your Need for Deep Sleep

The total number of hours you need to sleep changes with age. According to the Centers for Disease Control and Prevention (CDC), children and adolescents need more sleep than adults.

Sleep needs per age:

Sometimes, people think they may need less sleep during older adulthood, but this is not true. Older adults need seven to nine hours of sleep, but sometimes medical problems, likesleep apnea(pauses in breathing during sleep), may interfere with sleep, especially during older age.

How to Know How Much You Are Getting

You can learn how much sleep you are getting in several ways. You can gauge how you’re feeling the next day or use a device to get an approximate measure of your time spent in eachsleep stage.

The simplest and most common way to know if you’ve had enough sleep and enough deep sleep is based on how you feel in the morning. Long before electronic devices emerged for measuring sleep, people could often sense whether they got enough rest.

Signs that you’ve had enough deep sleep include:

Some signs that you might not have had enough sleep include waking up with a headache, feeling like a bright light is bothering your eyes, wanting to crawl back into bed, or feeling a little bit unsure if you are still dreaming.

What Is Sleep Inertia?Sleep inertiais that feeling you get when you first wake up and you still feel groggy or even a little confused. Waking up during deep sleep, especially if you haven’t had enough deep sleep, often causes sleep inertia.

What Is Sleep Inertia?

Sleep inertiais that feeling you get when you first wake up and you still feel groggy or even a little confused. Waking up during deep sleep, especially if you haven’t had enough deep sleep, often causes sleep inertia.

Diagnostic tests and tests of at-home devices can also detect if you have had enough sleep.

A comprehensivepolysomnogramis a diagnostic sleep study usually done in a sleep laboratory. This test measures your brain’s electrical activity, body temperature, heart rate, eye movements, and physical movements. Using these parameters, a sleep study can estimate your time in each sleep state.

At-home sleep devices include watches or rings that detect changes in your body temperature, physical movements, and heart rate that correlate with sleep stages. These devices provide a range of accuracy regarding your sleep stages.

I’m a Light Sleeper: Tips to Get Better Sleep

Sleep Stages and Deep Sleep

During a full night of sleep (or even during a nap), you experience several changes in your brain activity that are detected as brain waves. Additionally, your body goes through measurable physical changes. The brain wave changes correlate with changes in heart rate, body temperature, and physical movements.

Sleep stages are:

During a typical seven- to nine-hour night of sleep, most adults cycle through four to six cycles of non-REM (NREM) and REM sleep stages.

Is REM or Deep Sleep Better?There’s really no way to designate any sleep stage as being better than the others. All sleep stages are important for your memory and for your emotional and physical well-being.

Is REM or Deep Sleep Better?

There’s really no way to designate any sleep stage as being better than the others. All sleep stages are important for your memory and for your emotional and physical well-being.

During deep sleep, your body makes hormones (chemical messengers) and proteins that promote cell growth and renewal, for replenishing and healing your body’s tissues.

Processes during deep sleep include:

These different tasks can help your body maintain optimal function, producing new cells and tissue to replace those that need to be replaced. Additionally, repairing any injuries or damage to your body’s tissues helps prevent long-term disease.

Children experience a lot of growth during deep sleep. In addition to the growth of physical tissue, such as muscles, bones, and skin, deep sleep also helps with memory consolidation (new memories are turned into long-term memories) and improving daytime learning ability.

What Happens If You Don’t Get Enough Deep Sleep?

If you don’t get enough deep sleep, you will likely feel tired the next day. Being tired can feel different for different people, and your own self-awareness of feeling tired can differ, depending on your age, goals, and overall personality. You might feel sluggish, grumpy, agitated, or have trouble concentrating.

A chronic lack of deep sleep over a long period of time can gradually affect your physical and mental health. If you frequently feel irritable, unmotivated, or tired, this can interfere with your relationships with others, and you can also make you unproductive and depressed.

The physical effects of not getting enough deep sleep can lead to premature aging and may also impair your body’s ability to heal from injuries and illness.Eventually, this could lead to serious medical conditions, such as heart disease and cancer.

Sleep LatencySleep latencyis the amount of time it takes you to fall asleep. For typical healthy adults, it is between 10 and 20 minutes. If you are lacking a specific stage of sleep—especially deep sleep,you might fall into a deep sleep state immediately when you go to bed, rather than cycling through the earlier stages of sleep.So, a lack of deep sleep can cause you to miss out on other sleep stages, too.

Sleep Latency

Sleep latencyis the amount of time it takes you to fall asleep. For typical healthy adults, it is between 10 and 20 minutes. If you are lacking a specific stage of sleep—especially deep sleep,you might fall into a deep sleep state immediately when you go to bed, rather than cycling through the earlier stages of sleep.So, a lack of deep sleep can cause you to miss out on other sleep stages, too.

If you’re not getting enough deep sleep, you can consider strategies to increase your total and deep sleep time. Some daytime actions can impact your nighttime sleep, and you can change your sleep environment to help yourself get enough deep sleep.

Alcoholand caffeine are two common substances that interfere with deep sleep. Avoiding alcohol and caffeine in the evenings, or even throughout the day—at any time of the day or night—can help you get a natural sequence of sleep stages.

Other things you can do to help yourself get enough deep sleep include:

Try to clear your mind of anxiety before you go to bed. Since life almost always includes some difficulties, consider putting challenging or stressful tasks in a time slot for the next day to avoid anxiety while you’re trying to sleep.

Many people feel that heavy orweighted blanketsprovide a sense of relaxation, which can help you fall asleep. If you feel that the weight of heavy blankets helps you feel comfortable but makes you feel too hot, you could consider adjusting the room temperature so you can improve your overall sleep experience.

Summary

Deep sleep is important for your health, and even for your survival. Most adults spend about 20% to 25% of total sleep time in deep sleep stages, which include several blocks throughout a typical night of sleep. If you don’t get enough deep sleep, you could have an increased risk of health problems and may have a hard time recovering from illness or injury.

Strategies to get enough deep sleep include making sure your sleeping environment is comfortable, avoiding caffeine and alcohol before bed, and maintaining a relaxing routine before bedtime.

What Is Sleep Deprivation?

10 SourcesVerywell Health uses only high-quality sources, including peer-reviewed studies, to support the facts within our articles. Read oureditorial processto learn more about how we fact-check and keep our content accurate, reliable, and trustworthy.Sleep Foundation.Stages of sleep.Centers for Disease Control and Prevention.About sleep.Li J, Vitiello MV, Gooneratne NS.Sleep in normal aging.Sleep Med Clin.2022;17(2):161-171. doi:10.1016/j.jsmc.2022.02.007Shaw ND, Butler JP, Nemati S, et ak.Accumulated deep sleep is a powerful predictor of LH pulse onset in pubertal children.J Clin Endocrinol Metab.2015;100(3):1062-70. doi:10.1210/jc.2014-3563Gardiner C, Weakley J, Burke LM, et al.The effect of alcohol on subsequent sleep in healthy adults: a systematic review and meta-analysis.Sleep Med Rev.2024;80:102030. doi:10.1016/j.smrv.2024.102030Mao Y.Sleep architecture changes in diabetes.J Clin Med. 2024;13(22):6851. doi:10.3390/jcm13226851Agostini A, Centofanti S.Normal sleep in children and adolescence.Child Adolesc Psychiatr Clin N Am.2021;30(1):1-14. doi:10.1016/j.chc.2020.08.011National Institute Child Health and Human Development.What happens during deep sleep?Moffa A, Giorgi L, Nardelli D, et al.The potential impact of new remodelling intrapharynegal OSA surgery on sleep architecture: a preliminary investigation.Sleep Breath.2024;29(1):38. doi:10.1007/s11325-024-03222-xHarding EC, Franks NP, Wisden W.The temperature dependence of sleep.Front Neurosci. 2019;13:336. doi:10.3389/fnins.2019.00336

10 Sources

Verywell Health uses only high-quality sources, including peer-reviewed studies, to support the facts within our articles. Read oureditorial processto learn more about how we fact-check and keep our content accurate, reliable, and trustworthy.Sleep Foundation.Stages of sleep.Centers for Disease Control and Prevention.About sleep.Li J, Vitiello MV, Gooneratne NS.Sleep in normal aging.Sleep Med Clin.2022;17(2):161-171. doi:10.1016/j.jsmc.2022.02.007Shaw ND, Butler JP, Nemati S, et ak.Accumulated deep sleep is a powerful predictor of LH pulse onset in pubertal children.J Clin Endocrinol Metab.2015;100(3):1062-70. doi:10.1210/jc.2014-3563Gardiner C, Weakley J, Burke LM, et al.The effect of alcohol on subsequent sleep in healthy adults: a systematic review and meta-analysis.Sleep Med Rev.2024;80:102030. doi:10.1016/j.smrv.2024.102030Mao Y.Sleep architecture changes in diabetes.J Clin Med. 2024;13(22):6851. doi:10.3390/jcm13226851Agostini A, Centofanti S.Normal sleep in children and adolescence.Child Adolesc Psychiatr Clin N Am.2021;30(1):1-14. doi:10.1016/j.chc.2020.08.011National Institute Child Health and Human Development.What happens during deep sleep?Moffa A, Giorgi L, Nardelli D, et al.The potential impact of new remodelling intrapharynegal OSA surgery on sleep architecture: a preliminary investigation.Sleep Breath.2024;29(1):38. doi:10.1007/s11325-024-03222-xHarding EC, Franks NP, Wisden W.The temperature dependence of sleep.Front Neurosci. 2019;13:336. doi:10.3389/fnins.2019.00336

Verywell Health uses only high-quality sources, including peer-reviewed studies, to support the facts within our articles. Read oureditorial processto learn more about how we fact-check and keep our content accurate, reliable, and trustworthy.

Sleep Foundation.Stages of sleep.Centers for Disease Control and Prevention.About sleep.Li J, Vitiello MV, Gooneratne NS.Sleep in normal aging.Sleep Med Clin.2022;17(2):161-171. doi:10.1016/j.jsmc.2022.02.007Shaw ND, Butler JP, Nemati S, et ak.Accumulated deep sleep is a powerful predictor of LH pulse onset in pubertal children.J Clin Endocrinol Metab.2015;100(3):1062-70. doi:10.1210/jc.2014-3563Gardiner C, Weakley J, Burke LM, et al.The effect of alcohol on subsequent sleep in healthy adults: a systematic review and meta-analysis.Sleep Med Rev.2024;80:102030. doi:10.1016/j.smrv.2024.102030Mao Y.Sleep architecture changes in diabetes.J Clin Med. 2024;13(22):6851. doi:10.3390/jcm13226851Agostini A, Centofanti S.Normal sleep in children and adolescence.Child Adolesc Psychiatr Clin N Am.2021;30(1):1-14. doi:10.1016/j.chc.2020.08.011National Institute Child Health and Human Development.What happens during deep sleep?Moffa A, Giorgi L, Nardelli D, et al.The potential impact of new remodelling intrapharynegal OSA surgery on sleep architecture: a preliminary investigation.Sleep Breath.2024;29(1):38. doi:10.1007/s11325-024-03222-xHarding EC, Franks NP, Wisden W.The temperature dependence of sleep.Front Neurosci. 2019;13:336. doi:10.3389/fnins.2019.00336

Sleep Foundation.Stages of sleep.

Centers for Disease Control and Prevention.About sleep.

Li J, Vitiello MV, Gooneratne NS.Sleep in normal aging.Sleep Med Clin.2022;17(2):161-171. doi:10.1016/j.jsmc.2022.02.007

Shaw ND, Butler JP, Nemati S, et ak.Accumulated deep sleep is a powerful predictor of LH pulse onset in pubertal children.J Clin Endocrinol Metab.2015;100(3):1062-70. doi:10.1210/jc.2014-3563

Gardiner C, Weakley J, Burke LM, et al.The effect of alcohol on subsequent sleep in healthy adults: a systematic review and meta-analysis.Sleep Med Rev.2024;80:102030. doi:10.1016/j.smrv.2024.102030

Mao Y.Sleep architecture changes in diabetes.J Clin Med. 2024;13(22):6851. doi:10.3390/jcm13226851

Agostini A, Centofanti S.Normal sleep in children and adolescence.Child Adolesc Psychiatr Clin N Am.2021;30(1):1-14. doi:10.1016/j.chc.2020.08.011

National Institute Child Health and Human Development.What happens during deep sleep?

Moffa A, Giorgi L, Nardelli D, et al.The potential impact of new remodelling intrapharynegal OSA surgery on sleep architecture: a preliminary investigation.Sleep Breath.2024;29(1):38. doi:10.1007/s11325-024-03222-x

Harding EC, Franks NP, Wisden W.The temperature dependence of sleep.Front Neurosci. 2019;13:336. doi:10.3389/fnins.2019.00336

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